The mother of a Clare man (21) accused of murdering his sister (17) broke down in the witness box as she told a jury she didn't know why her son killed her daughter.
Giving evidence in the Central Criminal Court yesterday, Claire O'Dwyer said: "All we know is that something awful came over him."
"It wasn't our Pa," she added.
During the trial Mrs O'Dwyer, accompanied by her husband and daughter, has sat beside her son, Patrick O'Dwyer, of Shrohill, Ennistymon, Co Clare, who has pleaded not guilty to murdering his sister Marguerite at the family home on November 29th, 2004.
Mrs O'Dwyer told defence counsel, Mr Patrick Gageby SC, that the accused always obeyed her and was "very quiet" growing up. She said her son and deceased daughter were "like peas in a pod" and that "he really loved her". She described an occasion two weeks before the killing when the accused convinced her to allow her daughter out to celebrate her 17th birthday, despite the fact that she was doing her Leaving Certificate.
The accused's father, Paddy O'Dwyer, described a number of incidents to the court in which the accused's behaviour was unusual. These included frequently going into a "trance" while looking at Aertel, and another instance when his eyes were "rolling around his head" after he collapsed outside the house.
He also said his son told him he didn't know why he killed her.
"He said it was like looking at a video and that he couldn't do anything about it," he said.
Louise O'Dwyer, the older sister of the accused, described incidents to the court when the accused would turn his head during a "very ordinary" conversation and begin mumbling.
She said that when she asked him what he'd said, he wouldn't know what she was talking about.
Defence witness, consultant neurologist Dr Joan Moroney, said the accused told her that on the day of the killing, he had gone to his job as usual as a butcher's apprentice.
He told her he was still tired from having been drunk on the Saturday night and that he began "drifting off" into his own world at work. He told her he felt depressed that day, and that he was watching TV with his sister when he began to think about suicide. He said he picked up a hammer from the kitchen and planned to "bash his brains out" upstairs when he saw his sister in the sitting room and thought she would try to stop him.
He said he then hit her on the head with the hammer and couldn't remember the exact order of things after that.
Dr Moroney said she believed the accused suffered from epilepsy and that she based her opinion on an abnormal scan of brainwave activity and background information.
She said she did not believe the accused was having a seizure when he killed his sister because he could remember it.
But she also said seizures originating in the left temporal side of the brain could cause post-seizure behavioural changes in patients who suffered from this type of epilepsy.
Under cross-examination by prosecution counsel, Mr John Edwards SC, Dr Moroney admitted there was no way of knowing whether the accused had a seizure on the day of the killing, as his brain functioning would have had to be examined at the time for this to be determined.